A pupil-referral unit in Lancashire. Many pupils permanently excluded from school are sent to such units. Photograph: Christopher Thomond for the Guardian

On an average school day 511 pupils in primary, secondary and special needs schools across England are excluded for abusing or assaulting an adult, according to statistics from 2008-9.

On average, 503 of the exclusions are temporary. Of these, 412 are for verbally abuse or threats, while 91 are for physical assault. A further eight exclusions are permanent and are equally distributed between physical and verbal abuse. In total, 96,990 pupils are excluded each school year.

Ministers said the statistics, from the Department for Education, justified their view that plans to "restore discipline in classrooms" were long overdue.

In a white paper, published in the autumn, ministers said teachers would be allowed to use "reasonable force" or "physical restraint" to control a disruptive child. Headteachers would also have more say over whether an excluded pupil can return to a school. Pupils will no longer have a day's notice of an after-school detention and teachers will get extra powers to search pupils for mobile phones and other banned items.

However, a Labour spokeswoman said that discipline in schools had improved over the last 13 years. "Labour changed the law to give teachers greater powers to enforce discipline – including enshrining in law a teachers' right to punish misbehaviour," she said. The number of schools rated good or outstanding for discipline by Ofsted, the schools inspectorate, was 80%, she added.

Christine Blower, general secretary of the National Union of Teachers, said the only way that pupil behaviour would be "properly dealt with" would be to give teachers control of the curriculum and abolish league tables. "As long as league tables exist, there may be some pupils who are perceived as less desirable than others to a school," she said.

Chris Keates, general secretary of the NASUWT teaching union, said too many teachers felt they were managed "by those who have lost touch with the day to day reality of the classroom and who are too ready to blame the teachers rather than deal with the pupils".

As a whole, permanent exclusions – or expulsions – have dropped in state schools in recent years, but there has been a rise in temporary exclusions.

Last year a survey by the Association of Teachers and Lecturers found that more than three-quarters of primary school teachers believed pupils were becoming aggressive at an earlier age: 55% said behaviour had worsened over the past five years and almost two-thirds had witnessed physical aggression from pupils.

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